Preheat grill or side burner. Heat the oil in a large non-reactive saucepan over medium heat. Add the shallots and garlic and cook until soft. Add the Thai chiles, ginger, curry powder and cinnamon and cook for 2 minutes. Add the remaining ingredients and 1 cup of water. Cook until the sauce is reduced and thickened about 30 to 40 minutes, stirring occasionally. Remove from heat and let cool slightly.
Place plum mixture, in 2 to 3 batches, in a food processor and process until smooth, strain into a bowl and let cool to room temperature.
Bring water, soy, ginger, peppercorns, coriander, mustard seeds and salt and pepper, to taste, in a large saucepan and bring to a simmer.
Preheat grill to medium-high heat and preheat oven to 425 degrees F.
Rub oil on both sides of the ribs. Then rub each rack with the Asian Rub. Place racks onto preheated grill and allow to cook only until grill marks have been made.
Divide the water and soy sauce mixture between 2 roasting pans, place the ribs on a baking rack and set over the liquid in the pan. Roast the ribs in the preheated oven until about 3/4 of the way cooked, about 45 minutes, basting every 15 minutes.
Heat the grill to high.
Transfer the ribs to the grill and grill until the ribs are tender, about 45 minutes longer, brushing with the glaze during the last 10 minutes of cooking. Remove from the grill and brush with more of the glaze. Slice into ribs and garnish with green onions.
For the Asian Rub:
Whisk all ingredients together.
*If you cannot find ripe plums you can always use canned plums. If you cannot find plum juice you can always use cranberry juice.